Potassium Ion Batteries with Graphitic Materials

Graphite intercalation compounds (GICs) have attracted tremendous attention due to their exceptional properties that can be finely tuned by controlling the intercalation species and concentrations. Here, we report for the first time that potassium (K) ions can electrochemically intercalate into graphitic materials, such as graphite and reduced graphene oxide (RGO) at ambient temperature and pressure. Our experiments reveal that graphite can deliver a reversible capacity of 207 mAh/g. Combining experiments with ab initio calculations, we propose a three-step staging process during the intercalation of K ions into graphite: C → KC24 (Stage III) → KC16 (Stage II) → KC8 (Stage I). Moreover, we find that K ions can…

• NS
  National Science Foundation
• DO
  Division of Chemical, Bioengineering, Environmental, and Transport Systems

  Awards: 1335979, 1335944